Apparatus for temporarily retaining a thread segment having a pre-existing twist

ABSTRACT

An apparatus for temporarily retaining a thread segment of a twist yarn having a pre-existing twist in a manner which substantially preserves the pre-existing twist along a predetermined length of the thread segment in preparation for a selected thread or yarn joining operation is provided. The apparatus includes a stationary clamp surface member and a movable clamp surface member. The movable clamp surface member is movable relative to the stationary clamp surface member to form therewith a clamping extent in which the thread segment is clamped between the movable clamp surface member and the stationary clamp surface member. The clamping extent is dimensioned in correspondence with the length of the thread segment and may have, for example, a length corresponding to one-half the length of the predetermined length of the thread segment or about 35 to about 40 mm.

BACKGROUND OF THE PRESENT INVENTION

[0001] The present invention relates to an apparatus for temporarily retaining a thread segment of a twist yarn having a pre-existing twist in a manner which substantially preserves the pre-existing twist along a predetermined length of the thread segment in preparation for a selected thread or yarn joining operation.

[0002] In connection with the operations of spinning machines and doubling or twisting machines, as well as in connection with the beginning of the winding of a yarn package and a yarn break, it is necessary to maintain, for a predetermined time and a predetermined length, the twist in a spinning yarn or a doubled yarn so that this twist is still present upon the completion of the respective joining operation involving the spinning yarn or the doubled yarn. The objective of proceeding in this manner is to ensure that no, or at most only a very short, length of a yarn segment is present which does not possess the required twist. The presence of yarn segments having no twist can lead to the result, in some circumstances, that the entire spinning yarn or twist yarn package cannot be used in further textile material processing.

[0003] German patent document DE 41 14 069 A1 discloses a rotating yarn twist device having a yarn clamp device disposed immediately adjacent thereto—i.e., the yarn clamp device is secured to the yarn twist device—and the yarn clamp device acts in a substantially instantaneous manner to clamp a yarn end. This known yarn clamp device serves to hold the yarn end during the rotational yarn twist movement, that is, during a spin rotation movement. In connection with a near instantaneous clamping of a yarn end in this manner during a twist imparting process, it cannot be guaranteed that, upon release of the yarn end from its clamped disposition, the imparted twist over a certain length of the yarn extending from the yarn end will remain—i.e., it cannot be guaranteed that the twist will not be released or become untwisted.

SUMMARY OF THE INVENTION

[0004] The present invention provides an apparatus for temporarily retaining a thread segment having a pre-existing twist as a solution to the challenge of configuring an apparatus for temporarily retaining a thread segment of a twist yarn having a pre-existing twist in a manner which substantially preserves the pre-existing twist along a predetermined length of the thread segment in preparation for a selected thread or yarn joining operation such that the pre-existing twist in the thread segment is maintained or fixed for a long time and over a relatively long predetermined length of the thread segment.

[0005] To provide this solution, the apparatus for temporarily retaining a thread segment having a pre-existing twist of the present invention includes a stationary clamp surface member and a movable clamp surface member with the movable clamp surface member being movable relative to the stationary clamp surface member to form therewith a clamping extent in which the at least one thread segment is clamped between the movable clamp surface member and the stationary clamp surface member and with the clamping extent being dimensioned in correspondence with the length of the at least one thread segment.

[0006] To effect a “fixing” of the thread segment—that is, a retention of the thread segment in a manner that substantially preserves the preexisting twist thereof, the apparatus for temporarily retaining a thread segment having a pre-existing twist of the present invention operates in accordance with the principle of a “flat surface” clamping of a thread end as opposed to the principle of clamping the thread end at two spaced apart locations thereon.

[0007] The movable clamp surface member of the apparatus for temporarily retaining a thread segment having a pre-existing twist of the present invention is preferably configured to be mounted in a floating manner and the apparatus for temporarily retaining a thread segment having a pre-existing twist preferably includes a magnet for facilitating the movement of the movable clamp surface member from a non-clamping position in which it is spaced from the stationary clamp surface member to a clamping position in which the movable clamp surface member and the stationary clamp surface member clamp the thread segment therebetween.

[0008] If, in particular in accordance with one variation of the apparatus for temporarily retaining a thread segment having a pre-existing twist of the present invention, two units of the one embodiment of the apparatus for temporarily retaining a thread segment having a preexisting twist of the present invention are comprised in a single temporary yarn storage assembly which includes an angled block having two oppositely sloping surfaces with one sloping surface forming one stationary clamp surface member and the other sloping surface forming another stationary clamp surface member, then a permanent magnet is disposed adjacent the stationary clamp surface members and the movable clamp surface members comprise magnetic material.

[0009] The apparatus for temporarily retaining a thread segment having a pre-existing twist of the present invention can be used, in an advantageous manner, in connection with a method and an apparatus for producing a twist yarn in an integrated open end spinning and twisting process as disclosed in EP 0 701 014 B1 (U.S. Pat. No. 5,626,011), in the event that the apparatus for temporarily retaining a thread segment having a pre-existing twist is to handle a thread end still having its pre-existing twist which is inserted into a spinning rotor.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The object and advantages of the present invention will appear more clearly from the following specification in conjunction with the accompanying drawings, in which:

[0011]FIG. 1 is a perspective view of a single temporary yarn storage assembly comprised of two units of the one embodiment of the apparatus for temporarily retaining a thread segment having a pre-existing twist of the present invention;

[0012]FIG. 2 is an enlarged perspective view of the block of the single temporary yarn storage assembly and showing the floating mounting of the movable clamp surface members to the block;

[0013]FIG. 3 is a schematic view of the clamping and non-clamping positions of the movable clamp surface member shown in FIG. 2; and

[0014]FIG. 4 is a perspective view of one variation of the single temporary yarn storage assembly.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0015]FIGS. 1 and 2 show a single temporary yarn storage assembly comprised of two units of one embodiment of the apparatus for temporarily retaining a thread segment having a pre-existing twist of the present invention. The temporary yarn storage assembly is comprised of a substantially ridged roof shaped block 1 whose two sloped surfaces form the stationary clamp surfaces 2, 3. Each stationary clamp surface 2, 3 has a movable clamp surface member 4, 5, respectively, associated with it which comprises magnetic material. Each movable clamp surface member 4, 5 is mounted in a floating manner and has a rearwardly oriented tab 4.1, 5.1, respectively, each of which has a pair of cut-ins 4.2, 5.2, respectively, with each cut-in formed at one of the spaced apart ends of the respective tab at the transition location between the tab and the respective movable clamp surface member 4, 5. A plate 7 is secured to the block 1 by a screw 8. The plate 7, in correspondence with the sloped profile ridge surface of the block 1, has substantially the form of an equilateral triangle two of whose legs each extend parallel to a respective one of the sloped stationary clamp surfaces 2, 3. Each of these two legs of the plate 7 has a wing 9, 10, respectively, connected thereto which is angled outwardly relative to the block 1 and each wing has, as is illustrated with respect to the wing 10, an elongate, substantially right-angled cutout, such as the cut-out 10.1 of the wing 10. The tab 4.1, 5.1 of the movable clamp surface member 4, 5, respectively, extends into the cutout of the respective wing 9, 10 and is mounted in a hinge manner to the wing by its cut-ins 4.2, 5.2, respectively.

[0016] A permanent magnet 6 is mounted on the block 1 at a location such that magnetic attraction forces move the movable clamp surface members 4, 5 in a clamping movement in which the movable clamp surface member is moved relatively towards its associated stationary clamp surface 2, 3 for clamping a thread therebetween or such that magnetic attraction forces on the respective tab 4.1, 5.1 of the movable clamp surface member maintain the movable clamp surface member at an open spaced apart disposition from its associated stationary clamp surface 2, 3. The individual movable clamp surface members 4, 5 are movable between their respective clamping and non-clamping positions.

[0017] As seen in FIG. 1, a mount 20 mounts the temporary yarn storage assembly in its operational position on a textile machine frame or the like.

[0018]FIG. 3 schematically illustrates the movable clamp surface member 4, which is hingedly mounted in the cut-out 10.1 of the wing 10, in the clamping position in which the movable clamp surface member and the stationary clamp surface 2 compressively engage or clamp two thread segments A and B therebetween to thereby “fix” the thread segments. FIG. 3 also shows, in dashed lines, the clamp surface member 4′ and tab 4.1′ in a position where they have been pivoted away from the clamp surface 2.

[0019] As can be seen in FIG. 1, a thread loop having two loop branches A and B is disposed on the stationary clamp surface 2 in preparation for subsequent clamping of the thread loop between the movable clamp surface member 4 and the stationary clamp surface 2.

[0020] As seen in FIG. 4, to ensure a proper disposition of the two loop branches A and B, guide grooves are provided on the lower edges of the stationary clamp surfaces 2, 3 as is representatively shown by the guide grooves 2.1 formed on the stationary clamp surface 2.

[0021] The specification incorporates by reference the disclosure of German priority document 100 21 158.5 of Apr. 29, 2000.

[0022] The present invention is, of course, in no way restricted to the specific disclosure of the specification and drawings, but also encompasses any modifications within the scope of the appended claims. 

What I claim is:
 1. An apparatus for temporarily retaining a thread segment of a twist yarn having a pre-existing twist in a manner which substantially preserves the pre-existing twist along a predetermined length of the thread segment in preparation for a selected thread or yarn joining operation, comprising: a stationary clamp surface member; a movable clamp surface member, the movable clamp surface member being movable relative to the stationary clamp surface member to form therewith a clamping extent in which the one thread segment is clamped between the movable clamp surface member and the stationary clamp surface member, the clamping extent being dimensioned in correspondence with the length of the thread segment.
 2. An apparatus for temporarily retaining a thread segment having a pre-existing twist according to claim 1 , wherein the clamping extent corresponds to one-half the length of the predetermined length of the thread segment.
 3. An apparatus for temporarily retaining a thread segment having a pre-existing twist according to claim 1 , wherein the clamping extent has a length of about 35 to about 40 mm.
 4. An apparatus for temporarily retaining a thread segment having a pre-existing twist according to claim 1 , wherein the movable clamp surface member is mounted in a floating manner and the apparatus for temporarily retaining a thread segment having a pre-existing twist includes a magnet for facilitating the movement of the movable clamp surface member from a non-clamping position in which it is spaced from the stationary clamp surface member to a clamping position in which the movable clamp surface member and the stationary clamp surface member clamp the thread segment therebetween.
 5. An apparatus for temporarily retaining a thread segment having a pre-existing twist according to claim 2 , and further comprising a permanent magnet disposed adjacent the stationary clamp surface members and the movable clamp surface member comprises magnetic material.
 6. An apparatus for temporarily retaining a thread segment having a preexisting twist according to claim 1 , and further comprising a second movable clamp surface member and an angled block having two oppositely sloping surfaces, one sloping surface forming the stationary clamp surface member and the other sloping surface forming another stationary clamp surface member, each movable clamp surface member being mounted relative to a respective one of the stationary clamp surface member for movement relative thereto to effect clamping and release of a thread segment between the movable clamp surface member and the stationary clamp surface member.
 7. An apparatus for temporarily retaining a thread segment having a pre-existing twist according to claim 1 , and further comprising a tab connected to the movable clamp surface member, the tab having a pair of cut-ins each formed at one of the spaced apart ends of the tab at the transition location between the tab and the movable clamp surface member and an outwardly angled wing having an elongate, substantially right-angled cut-out, the tab of the movable clamp surface member extending into the cut-out of the wing and the movable clamp surface member being mounted in a hinge manner to the wing by its cut-ins.
 8. An apparatus for temporarily retaining a thread segment having a pre-existing twist according to claim 1 , wherein the movable clamp surface member is resiliently biased toward its clamping position with the stationary clamp surface member. 